Limping is a deviation from the normal gait pattern.
Limping may be caused by pain, weakness, restricted joint movement or deformity.
The doctor should be able to suspect the condition and refer for further emergency investigations children with a bacterial infection of the bones or joints, leukaemia or malignant tumours, hip epiphysiolysis or suspected physical abuse.
Mild pain in children below about 7 years of age at bedtime in the absence of other symptoms or findings usually represents benign “growing pains” Innocent Limb Aches (Growing Pains) in Children.
Painless limp
Structural cause (limb length discrepancy, malposition of lower limbs, restricted joint movement, developmental disorder of the hip joint)
Mild normal variation in childhood growth and development (genu valgum, genu valgum, low plantar arch, walking with the feet turned inward) does not generally cause or explain limping.
Clinical examination
Clinical examination must be carried out in a systematic way.
Small children cannot localise pain.
Referred pain is common (hip joint problems in particular are typically felt as pain in the thigh or knee).
The history given by parents may be misleading.
The systematic approach should always include
examining small children in particular in their underwear
an examination of the back and a bilateral examination of hips, knees, lower legs and feet regardless of the site of the pain.
Small children should first be allowed to play freely in the examination room while you observe how they move.
During the actual examination, depending on the child's age, the child can either be held by a parent or on the examination table.
The symptomatic limb should be examined last.
The child should be asked to walk (including on the toes and on the heels) and to squat.
When limping, the child will try to reduce the heel strike by lowering the foot with the ball of the foot first and make sure that their weight will be on the painful leg as briefly as possible.
The Trendelenburg sign is positive if the pelvis tilts towards the symptomatic limb (picture F1).
When the weight is on the healthy limb
An abnormal Trendelenburg's test result F1 is suggestive of hip pathology or weakened muscle power in the pelvic region.
Inability to walk on the toes or heels is suggestive of foot pain, limited range of motion or reduced muscle power. The child may compensate for the difference in length of their lower limbs by standing on the toes of the shorter limb.
Spinal mobility and postural defects (scoliosis Scoliosis and Kyphosis) can be checked by inspecting the back from behind as the child bends forward. Any limb length discrepancy should be noted at the same time.
Limb examination
Muscle atrophy
Local swelling/masses
Intra-articular effusion, redness and heat
Signs of injury
Foreign bodies in the sole of the foot
Ranges of joint motion (comparing the symptomatic side to the healthy side)
Further investigations
If the child has no general symptoms and there are no abnormal findings, the situation can be monitored.
If there are any abnormal findings in the above examinations, x-ray examination of the symptomatic area is indicated.
Limping of unclear origin or refusal to walk lasting for more than 2 weeks in the absence of any of the above general symptoms or symptoms of infection.
References
Payares-Lizano M. The Limping Child. Pediatr Clin North Am 2020;67(1):119-138 [PubMed]
Bartoloni A, Aparisi Gómez MP, Cirillo M, et al. Imaging of the limping child. Eur J Radiol 2018;109():155-170 [PubMed]